1. Field of the Invention
The present invention relates to an incinerator, and particularly to an incinerator that is capable of economically incinerating city garbage and industrial waste including high polymer waste such as plastics with low cost, and is capable of fully preventing dioxins from being generated.
2. Description of the Prior Art
Guideline for Preventing the Generation of Dioxins in Waste Processing, enacted in 1997 to regulate the processing of wastes in Japan, stipulates that permissible emission of dioxins is within 0.1 ng-TEQ/Nm3 for newly built incinerators (full-continuous type). It is also stipulated that an incinerator must be operated under the following conditions: combustion temperature of 850° C. or higher (preferably 900° C. or higher), retention time of 2 seconds or longer, CO concentration of 30 ppm or lower and stable combustion under continuous monitoring.
To comply with the guideline described above, the present applicant filed Patent Application No. 10-126574 (Japanese Unexamined Patent Publication (Kokai) No. 11-294745) on Mar. 31, 1998.
The invention of Japanese Unexamined Patent Publication (Kokai) No. 11-294745 provides an intermediate baffle WI that is made of a refractory material and is included in a combustion chamber D of an incinerator, while unburned gas generated in the combustion chamber D is introduced into a recombustion chamber C and is burned at a high temperature therein, so that pollutants are thermally decomposed. Since the intermediate baffle WI terminates at a middle portion in the furnace and clear separation is not provided between the combustion chamber D and the recombustion chamber C, there has been such a problem that unburned gas that includes much CO generated in the combustion chamber D and ash content included in the unburned gas are discharged to the outside through the recombustion chamber C without being sufficiently burned in the recombustion chamber C. Release of the gas that includes CO may involve dioxins and has been a problem to be solved.
With this background, an object of the present invention is to provide an incinerator that can eliminate the drawbacks of the incinerators of the prior art and substantially prevent dioxins from being released, while requiring less fuel supply for higher economy.